I just finished an update, which contains the improvements for the buddypress search as well. On top of that there are 4 options now: 'OR', 'AND', 'OR – exact words', 'AND – exact words'. This is a huge step forward and it's not yet properly tested. The update instructions are the same as before.
On top of that there are options now to enable/disable the search in public, private and hidden buddypress groups.
Try out the 'AND' or the 'AND – exact words' option on the General option->Behaviour tab, one of them will suit your needs for sure.Best,
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