This is a reason to use a new Table Occurrence.
When in your relationship graph you can select a table, then you click the double plus icon at the bottom.
This creates a new Table Occurrence.
Please understand that this DOES NOT create a new table. It's simply an occurrence of that table so you can use it to create different relationships.
Creating new Table Occurrences (TO's) can also be done to keep your relationship graph more organised.
Please beware that when you need data that comes through this new relationship you also need to reference that new table occurrence. So it's best to correctly / clearly name your table occurrences.
Thanks a lot for your help. I really appreciate your time.
In fact I only needed to know that what I needed was really related to "table occurrences". Your post gave me the green light and then with a bit of trial and error I figured out what to do.
I created a few other table occurrences of my "staff" table and associated them with the other tables. So far it works perfectly fine!
Many thanks again!