Calling Provider in another Provider: Bad Practice or OK?

Is it considered bad practice to import a provider in another provider and allow the 2, 3, whatever, to interact within one indvidual provider? Or, no problem?

I would say no problem as long as provider A is used in more than one place. IOW, if provider A is only used by provider B, there is no point in it pretending to be independent and should be folded into provider B.

Much to the point of dependency injection