I'm setting up a project planning system. The Project list has two sub-lists, Resource and Activity.
I've successfully created the form for these, so the information can be entered and edited. Both sub-lists are List or Library controls on the main Project form.
The Resource child list has a field for which activity it is relevant to. (Resource Name, Stage, Activity, lookup to parent ProjectID)
The Activity list has just Activity Name, Stage, Status, lookup to parent ProjectID.
I have created a lookup from the Resource list to the Activity list, but it shows all activities across all projects.
How can I filter the Resource sub-list activity lookup dropdown to only show activities attached to the Project (ProjectID)?