I have the following 4 Forms

System Access - User ID, User Email (both set by system), First Name, Last Name (input by user)

Membership - First Name, Last Name, Licence (input by user, can be different to System Access) and a Lookup field to System Access form with multi select enabled.

Nomination - Logged in User (set by system)

Entry - Sub Form of Nomination, fields are Licence (choice field), First Name (text), Last Name (text)

The end result I am trying to work out is that on the Nomination/Entry form, the only value/s that should show up in "Licence" on the sub form are the ones where the Membership records contains the logged in user from the Nomination Form.  I can't for the life of me work out what to do.

I hope I have explained it clearly enough, I have attached an image of the forms to try and make it more clear.

Cheers

Aaron