To understand better:
Sheet 1 lists Practices. User selects a practice, and sheet 2 lists all the doctors at that practice.
You want sheet 3 to take the Specialty of the Practice from sheet 1 and display stuff about that specialty.
Correct? (So you want one selection to control the next two sheets.)
Can a practice have more than one specialty?
Let's start with clarifying these questions first.
BTW, you're talking about a filter. But I was thinking about filter actions. (First sheet lists all practices, and the user clicks on a practice on that sheet, rather than using a filter to display only one practice on sheet 1.)
Maybe it would be best if you can upload a sample workbook. If your data contains proprietary info, anonymize it. The video linked here shows a simple way to do that:
Sheet 1 and 2 are combined, it lists the practice with all the doctors, the quick filter is on Practice. So yes I want the specialty from sheet 1 and display stuff on that specialty on sheet 2. Yes, they can have more than one specialty.
I can't wrap my head around this.
Can you upload a sample workbook so I can see it hands-on?