For some reason, filtering subgrids (Turbo Forms / non-legacy JS engine) in CRM 9.0 is not implemented (yet?!). A temporary solution for on-premise version would be implementing the addCustomFilter function from the C:\Program Files\Dynamics 365\CRMWeb\_static\form\formcontrols.js library. Current implementation: addCustomFilter: function(fetchXmlFilter) { throw Error.notImplemented(‘The method or operation is not implemented.’); }, Fix: addCustomFilter: function(fetchXmlFilter) { //… Continue reading CRM 365 9.0 filtering subgrids (Turbo Forms)