How do you cook Posole so its tender like canned ones?

The Rancho Gordo hominy has already been limed. I soak mine overnight (have done less) and cook a couple hours or so. It comes out tender but still has chewy texture--I prefer it to canned. You can tell when it is done as some of the kernels "explode" and turn inside out so to speak.
It sounds like you are doing it right, you may just prefer a softer consistency. By the time you have presoaked it, cooked it, and then cooked again with your pozole ingredients, it should definitely be done!

Hominy is made by the process known south of the border as nixtamalization- so you do not need to soak it further in lime. You do actually really need to soak it for at least 8-12 hours, and I prefer to soak mine in a brine solution. I also think you probably will need to cook it in a pressure cooker or Instant Pot to get it to a softer consistency, though I rather doubt you are gong to get quite the softness of a canned product. I imagine part of the reason it may be a slightly different texture in Mexico may have to do with how dry or how old the product is. Just like any dried product, think beans, the longer it's dried before cooking, the less tender it's likely to cook up.

Did you soak the hominy as directed by Rancho Gordo instructions? Looks like they need an 8 hour soak and then simmer for 2 hours until chewy and tender. It might be that RG hominy will not get tender like the canned stuff. If you have a pressure cooker, I would cook for 1 hour in a pressure cooker.