I’m the mod of a ~70k page group that relates specifically to my career, how can I use this to grow my own individual page using paid and non-paid advertising?

As per the title, I'm the mod and "top member" (most posts) of a Facebook group. The existing admin doesn't want to monetise the page and the group is private which limits post reach.

The page relates perfectly to my current job and qualifications, so I'm an expert in the group – which is why the admin made me a mod.

How can i use my membership in this group to grow an individual page?

My thoughts were to add my own business page and comment within the group on that, however the admin has stopped pages joining?. I think could also post reels. If people have watched my reel I can use paid advertising to retarget them to try to convert them, but is there a way to advertise specifically to a groups members using paid advertising?