Partially buy/sell real estate inheritance community?

Probably an unusual question that does not occur very often, but maybe someone has experienced this before.

A building plot consisting of 2 parcels, each of which belongs half to 2 parties of a community of heirs. Which half belongs to whom is not defined in the land register, only that each parcel belongs half to the other.

Is there even the possibility that one of the two parties sells at least the respective share, even if it hardly benefits anyone?

Or can the property only be sold completely, and only if both parties agree to the sale?

As long as the [Erbengemeinschaft] exists, everything belongs to both together. The individual can hardly do anything without the consent of the respective other. However, if the heirs do not get along, a partition auction can be requested without the consent of the other, during which the entire property will be auctioned off even against the will of the other.