How to sponsor parents via spouse?

My sister is married to a US citizen and she has a conditional green card. Can her husband sponsor my parents who are undocumented (legal entry, expired visa)?

They've been married for almost 2 years and she's had the conditional green card for about a year. She had DACA prior to being married.

Thank you for all your inputs.

No. Son in law is not a relative. The way about this would be.

Sister's husband sponsors sister.
Sister gets conditional green card.
After 2 years they file for removal of conditions.
After 1 more year she filed for naturalization.
Once she's a US citizen she sponsors her parents.

This.

The parents would AOS...
(no need for AP)