Do you have access to a 45 degree back extension? The way Bret Contreras explains how to do them prioritizes the hamstrings and glutes as opposed to the typical way of doing them, It’s very similar to a GHR, but with a different angle.
You could also look into doing Nordic Hamstring Curls, RDL’s, or cable pull throughs . These work the hamstrings in hip extension. I personally like to do hamstring curls as well.
