Advanced sorting

I've been building a database to store and sort photos for books and exhibitions, which is now working very well - I save as PDF and have a high-res scrollable file I can load onto my iPad or other device. I start out by pasting photos and applying labels to fields. It works really well to a point, and that is sorting the order. I have three primary fields: [Project title], [location], [sub-location]. This is easy to create as I go along but then its time consuming to sort as a sequence after that. I need a process to sequence the photos into location>sub-location then sequence (1,2,3). I guess I could sort on label order in the location>sub-location fields, then do a sequence (number) sort after that, but is there other options I've not thought of? I have a number of projects in progress in the same database so it would be a lot of work, and just want to get an idea of what else might be an option before committing to a particular scheme. For example, using some sort relationship tables to manage the label orders, and cascading labels so that selecting say 'Bridge Walk' in the Project field loads the set of 'location' dropdown labels that again loads the loads the 'sub-location' dropdown labels.

As an example; for photos of thousands of people marching across a bridge, the sequence of sub-location labels would be:

Pre-bridge travel

Up ramp

On bridge

Exit ramp

Along Flyover

Park assembly

After that sequence is ordered based on sub-location, there would be sequencing order within each set

On bridge 1,2,3.....15 (etc Sequencing field in each record)

Anyway, any ideas would be appreciated. I use FMPro 15.

Edited January 6, 20242 yr by VirtualBob