If you are looking for a simpler solution that only allows for changing the fetchXML used by the lookup control check out James's post at CRM 2011 Change SubGrid FetchXML.
I had hoped that Microsoft would provide support for applying custom views to the lookup used by sub-grids, since you can use the Xrm.Page.ui.addCustomView method to apply a custom view to a lookup control. Unfortunately, the Xrm.Page.ui.addCustomView method only works for lookup controls. So for the past three full days I have spent my time trying to understand how the addCustomView method works so I could extend it to support sub-grids. The code below does this; however, IT HAS BEEN TESTED MINIMALLY and thus may not address your particular case. If you find issues or improve this please let me know so I can share it with the rest of the community.
//Warning: This code below is not supported by Microsoft
//Place this code in the onload event of a form containing a sub-grid that you wish to filter
window.attachEvent("onload", function() {
function locAssocObj_custom(iType, sSubType, sAssociationName, iRoleOrdinal, additionalParams, showNew, showProp, defaultViewId, customViews, allowFilterOff, disableQuickFind, disableViewPicker, viewsIds) {
var lookupItems = LookupObjects(null, "multi", iType, 0, null, additionalParams, showNew, showProp, null, null, null, null, defaultViewId, customViews, null, null, null, null, allowFilterOff, disableQuickFind, disableViewPicker, viewsIds, false);
if (lookupItems) lookupItems.items.length > 0 && AssociateObjects(crmFormSubmit.crmFormSubmitObjectType.value, crmFormSubmit.crmFormSubmitId.value, iType, lookupItems, iRoleOrdinal == 2, sSubType, sAssociationName)
}
if (Mscrm.GridRibbonActions.addExistingFromSubGridAssociated) {
Mscrm.GridRibbonActions.addExistingFromSubGridAssociated_org = window.Mscrm.GridRibbonActions.addExistingFromSubGridAssociated;
window.Mscrm.GridRibbonActions.addExistingFromSubGridAssociated = function(gridTypeCode, gridControl) {
if (IsNull(gridControl)) {
throw Error.argument("value", "gridControl is null or undefined")
return;
}
//Check if a filtered grid. If not call default method
if (IsNull(gridControl._element.isFiltered) || !gridControl._element.isFiltered) {
Mscrm.GridRibbonActions.addExistingFromSubGridAssociated_org(gridTypeCode, gridControl)
} else {
var e = document.getElementById(gridControl._element.id);
var showNew = (IsNull(e.showNew) ? null : e.showNew);
var showProp = (IsNull(e.showProp) ? null : e.showProp);
var allowFilterOff = (IsNull(e.allowFilterOff) ? null : e.allowFilterOff);
var disableQuickFind = (IsNull(e.disableQuickFind) ? null : e.disableQuickFind);
var disableViewPicker = (IsNull(e.disableViewPicker) ? null : e.disableViewPicker);
var customViews = (IsNull(e.customViews) ? null : e.customViews);
var defaultViewId = (IsNull(e.defaultViewId) ? null : e.defaultViewId);
var viewsIds = null;
var $v_0 = gridControl.getParameter("relName"), $v_1 = gridControl.getParameter("roleOrd"), $v_2 = false;
switch (gridTypeCode) {
case Mscrm.EntityTypeCode.List:
switch ($v_0) {
case "campaignactivitylist_association":
window.parent.locAssocObjCampaignActivity(gridTypeCode, "", $v_0, $v_1);
break;
case "campaignlist_association":
locAssocObjCampaign(gridTypeCode, "subType=targetLists", $v_0, $v_1);
break;
case "listlead_association":
window.parent.locAssocObjLead(gridTypeCode, "", $v_0, $v_1);
break;
case "listcontact_association":
window.parent.locAssocObjContact(gridTypeCode, "", $v_0, $v_1);
break;
case "listaccount_association":
window.parent.locAssocObjAccount(gridTypeCode, "", $v_0, $v_1);
break;
default:
$v_2 = true;
break
}
break;
case Mscrm.EntityTypeCode.Campaign:
switch ($v_0) {
case "campaignlist_association":
locAssocObjList(gridTypeCode, "subType=targetLists", $v_0, $v_1);
break;
case "campaigncampaign_association":
locAssocObjCampaign(gridTypeCode, "", $v_0, $v_1);
break;
default:
$v_2 = true;
break
}
break;
case Mscrm.EntityTypeCode.Product:
switch ($v_0) {
case "productsubstitute_association":
locAssocObjProduct(gridTypeCode, "", $v_0, $v_1);
break;
case "productassociation_association":
locAssocObjProduct(gridTypeCode, "", $v_0, $v_1);
break;
case "campaignproduct_association":
locAssocObjCampaign(gridTypeCode, "", $v_0, $v_1);
break;
case "competitorproduct_association":
window.parent.locAssocObjCompetitor(gridTypeCode, "", $v_0, $v_1);
break;
default:
$v_2 = true; break
}
break;
default:
$v_2 = true;
break
}
if ($v_2) {
var $v_3 = locAssocObj_custom;
var additionalParams = null;
//$v_3(gridTypeCode,"",$v_0,$v_1, additionalParams)
$v_3(gridTypeCode, "", $v_0, $v_1, additionalParams, showNew, showProp, defaultViewId, customViews, allowFilterOff, disableQuickFind, disableViewPicker, viewsIds);
}
}
}
}
});
function addSubgridCustomView(subgridID, entityTypeCode, displayName, fetchXML, layoutXML, filterType, isDefault) {
/// <summary>
/// Adds a custom view to lookup page used by a subgrid
/// </summary>
/// <param name="subgridID" type="string">
/// ID of sub-grid to add custom view to
/// </param>
/// <param name="entityTypeCode" type="int">
/// The entity type code returned by the fetch statement
/// </param>
/// <param name="displayName" type="string">
/// The name to use for the view
/// </param>
/// <param name="fetchXML" type="string">
/// The fetch XML to be used by the view
/// </param>
/// <param name="layoutXML" type="string">
/// The layout XML to be used by the view.
/// If layoutXML == null the layout from the default view of the entity will be used
/// </param>
/// <param name="filterType" type="int">
/// Type of custom view. Default is 0
/// </param>
/// <param name="isDefault" type="boolean">
/// The layout XML to be used by the view.
/// If layoutXML == null the layout from the default view of the entity will be used
/// </param>
/// <returns type="nothing" />
if (IsNull(subgridID)) { throw Error.argument("value", "ID of sub-grid to filter not provided") ; return; }
if (IsNull(entityTypeCode)) { throw Error.argument("value", "Entype code of returned object by fetchXML not provided"); return; }
if (IsNull(fetchXML)) { throw Error.argument("value", "FetchXml not provide for custom view on sub-grid"); return; }
if (IsNull(layoutXML)) { throw Error.argument("value", "LayoutXml not provided for custom view on sub-grid"); return; }
var grd = document.getElementById(subgridID);
//Check if the sub-grid has any customViews already.
var customViews = (IsNull(grd.customViews) ? new Array() : grd.customViews);
var oScriptlet = new ActiveXObject("Scriptlet.TypeLib");
var viewId = oScriptlet.GUID.toString().substr(0, 38); //Call substr to address issue of trailing white space
//Create an object to hold the customView's information
var customView = new Object();
customView.fetchXml = fetchXML;
customView.id = viewId;
customView.layoutXml = layoutXML;
customView.name = (IsNull(displayName) || displayName == "" ? "Filtered Lookup" : displayName);
customView.recordType = entityTypeCode;
customView.Type = (!IsNull(filterType) ? filterType : 0);
//Add the customView object to the array of customViews
customViews.push(customView);
//Add the array of custom views to the sub-grid
grd.customViews = customViews;
//Set this view as the default if desired
if (isDefault) { grd.defaultViewId = viewId; }
}
var fetchXML = "<fetch version='1.0' output-format='xml-platform' mapping='logical' distinct='false'>";
fetchXML += "<entity name='account'>";
fetchXML += "<all-attributes />";
fetchXML += "<filter type='and'>";
fetchXML += "<condition attribute='name' operator='like' value='test%'/>";
fetchXML += "</filter>";
fetchXML += "</entity>";
fetchXML += "</fetch>";
//Build the layout to use in the lookup. Keep in mind that you will need to know the Object Type Code
//and the primary key of object displayed
var layoutXML = "<grid name='resultset' object='1' jump='name' select='1' icon='1' preview='1'>";
layoutXML += "<row name='result' id='accountid'>";
layoutXML += "<cell name='name' width='300' />";
layoutXML += "</row>";
layoutXML += "</grid>";
//Apply custom view / lookup filter to the grid
addSubgridCustomView("#GRID_ID#", #OBJECT_TYPE_CODE#, "Test", fetchXML, layoutXML, 0, true);
