Hi Harry,
I don't think this is possible to move only one entry, below screen shot see (*) key value field , Its not editable, if that is editable we can mentions particular BF and we can move particular BF. SAP not allowing to do edit because there may be dependencies and conflicts will come . *(star) means will move all BFs from this to SFW_ACTIVE_B2 to target system.
Thanks
Siva