SEOmatic page parent?
Yep, you should definitely be able to do what you want.

What I do is I test the code in the actual Twig template used to display the page, and then once I have it working, I paste it into the SEOmatic field, and add object. in front of the entry.

e.g.: If this gives you the results you want in the template:

{{ entry.title }} | {{ entry.parent.title }} | Company Name


Then when you paste it into SEOmatic's CP fields, it'd look like this:

{{ object.entry.title }} | {{ object.entry.parent.title }} | Company Name


I find that this makes it easier to debug.