Hi, this is an interesting request. The other team members who have been around longer will know if this is regularly mentioned or not. I don’t think there is currently a way to tie any one property’s options to the value in another property.
The easiest way is to skip the second property idea, and just make one big custom vocabulary with entries like “Government 1: Place 1”, “Government 1: Place 2”, “Government 2: Place 1,” etc.
And trust that people will sort through to find the one they need.
If you really want it to be more rigorous than that … You would need a custom vocabulary for each government that lists all the locations in that government. You could do that two ways:
by creating lots of resource templates (one for each government) and having the properties in those resource templates linked to different custom vocabularies.
Custom Vocab - Omeka S User Manual
This is an unwieldy solution unfortunately. The good news is it’s really not that hard to get a base resource template how you like it, export it, then import it back in with a different government label each time, and manually edit each to choose the appropriate custom vocabulary. Just time-consuming.
by creating the same custom vocabs as above, but with a custom ontology that publishes your own properties like “Place (Government 1)” and “Place (Government 2)” that are all included in one resource template. Then your items just use one property or another as required. And you can hide the internal property labels with an alternate in the resource template. Also unwieldy, but maybe less time-consuming.
Omeka S - Custom Ontology
But, this would frustrate people who want to search by the field “Place” and don’t realize it’s multiple properties internally.