CRM 2015 online does not have the Related records feature. Under Sales -> Opportunities, we selected an opportunity and have a custom lookup field added. This field display few records and "Lookup More Records" as an option.
When we click on the "Lookup More Records" inside a lookup control, an inline dialog popup is displayed which has three controls in it. The controls are Lookup For, Lookup Views, and Subgrid displaying the list of items.
Now, we would like to disable Lookup for with a specific Entity selected. How do we go about doing this?