French term (edited): dépens, liquidés à l\'indemnité de procédure, elle-même non liquidée

The "l'indemnité de procédure" cost is the amount paid to the winning party to cover their attorney costs only. The judge fixes the amount based on certain factors, such as the ability of the other party to pay etc.

Therefore I would translate it as "costs, paid at the standard "procedural indemnity" amount, which itself may vary."

References

"L'indemnité de procédure est une somme d'argent payée par la partie qui a perdu le procès, destinée à couvrir une partie des frais d'avocat de la partie qui a gagné. Elle doit être demandée au juge, qui en fixe le montant selon certains critères prévus par la loi, tels que l'enjeu de la demande, la capacité financière de la partie qui doit la payer, la complexité de l'affaire, etc. En matière de sécurité sociale, l'indemnité de procédure est forfaitaire. " https://www.droitsquotidiens.be/fr/lexique/indemnite-de-proc...

"The Belgian Judicial Code expressly recognises the "loser pays" principle, under which the unsuccessful party must cover the costs of the proceedings. Therefore, court costs are usually borne by the unsuccessful party.
Attorneys' fees are paid as a flat-rate indemnity (rechtsplegingsvergoeding/indemnité de procédure). The amount of the indemnity depends on the type and importance of the claim. The court can deviate from the standard indemnity on a party's reasoned request, but must comply with the minimum and maximum amounts set in a royal decree. For example, for a claim valued between EUR100,000 and EUR250,000, the standard indemnity for attorneys' fees is EUR6,000. The court can reduce this amount to a minimum of EUR1,200, or increase it up to a maximum of EUR12,000. In its assessment, the court can take into account the following factors:
Financial capacity of the unsuccessful party (to reduce the amount of the indemnity).
Complexity of the case.
Contractual compensation awarded to the successful party.
Obviously unreasonable nature of the situation." https://uk.practicallaw.thomsonreuters.com/w-013-2762?transi...

French term (edited): condamner ... aux dépens, liquidés à l'indemnité de procédure, elle-même non liquidée

condamner ... aux dépens, liquidés à l'indemnité de procédure, elle-même non liquidée
=
to condemn (the other party) to pay [our] costs, [to be] determined as including only the "procedural indemnity", [the amount of] which [= "l'indemnité de procédure "] is yet to be determined



... aux dépens, = condemned to pay costs

liquidés à l'indemnité de procédure, = [costs being] determined as (including only) "l'indemnité de procédure / the "procedural indemnity" [implied: nothing else is to be included - no lawyers fees, no experts fees, nothing else]

elle-même non liquidée = [the amount of] which [= "l'indemnité de procédure "] is yet to be determined

CL5 about the meaning, some other wording is not excluded.

see refs.