All aspects of the divorce must be handled in Beis Din, including the actual divorce/gittin issuing, assets dispersal, custody decisions, etc. And the must be in accordance of Torah/halacha only.
Once any party attempts to circumvent the above, by going to a secular court for monetary issues, custody issues, etc., they lose their standing to make any demands in Beis Din, including for a Get issuance.
They cannot demand halacha be upheld only in the issuance of the get, but halacha not be upheld in asset dispersal or custody decisions.