You can be on Lexi Path for Valeria scenes, she doesnt care about Alexis, she only cares about Layla.
Layla romance path locks you out of basically all Valeria content: Swimsuit Pic, Booth scene, Phone call in her house, "Date" on the beach. You can also get to the 2nd beach scene on Laylas path with the secret path for Alexis (unlocks if you ignore Alexis on the plane and dont romance Erynn during the Hot Tub scene with Layla), but Valeria will basically ignore you.
On Alexis path you can get all these scenes and she looks over to you several times during the Erynn/Alexis/Iris scene.
So as of now Alexis + Valeria works, Layla + Valeria doesnt.
For most content in the next Updates you probably want a Layla Romance + Alexis Secret Path and then one for Alexis Romance + Valeria Romance Path, since it seems like you can be on Erynns Romance Path regardless, she just acts slightly different if you date Alexis, but the path is clearly still the Romance Path. Even in the Layla + Secret Alexis Path while she is trying to hook you up with her shes more than flirty herself.