Many operators ask similar questions on how to filter spots in the DX Cluster. Setting spot filters are done from the "SERVER" end and not within HRD directly. Each DX Cluster NODE runs different node software. Mike, WA9PIE, one of the HRD owners owns and operates the WA9PIE-2 DX cluster node, which runs the DX Spider software. He has produced videos on our YouTube channel to demonstrate the use of these filters on HIS DX Spider node. He has also answered many questions in the HRD Forums pertaining to this very topic.
As an example, if an American only wanted to see spots sent from other hams in the operator's country/area, and if the operator didn't want to see spots for US callsigns (in other words, DX spots sent by US hams for only foreign callsigns), then the filters would be set up something like this:
reject/spot 1 call_dxcc w (this command rejects spots FOR stations with USA callsigns)
accept/spot 2 by_dxcc w,ve (this command accepts only spots FROM stations with USA or Canadian callsigns)
Alternately, the last could be "accept/spot 2 by_zone 3,4,5", which only accepts spots from CQ Zones 3, 4 & 5.
You can clear your filters by typing "clear/spots all".
The DX Spider filtering manual can be found here: http://www.dxcluster.org/main/filtering_en.html
For examples, watch the tutorial video and you should understand more.
DX Cluster FeaturesVideo: https://www.youtube.com/watch?v=1MenkUd1rDc