If you can glulam them (You'll need to get decently plane surfaces and some serious clamping) then you could treat the resulting timbers as if they were larger ones. Otherwise it depends on the use. For stud framing where the built-up posts will be joined to the rest of the structure with nails or brackets I don't see a problem (They're just bearing vertical loads). If you were wanting to cut traditional joinery into them I'd be a lot less sure. If it were me, I'd want to look at each post in turn to be certain about what the joinery would look like.

*Note: These are the opinions of an unqualified amateur TF with no knowledge of American building codes. If your building needs to be certified in some way you'd want to have this conversation with a / your engineer.