To “filter” (in this sense) is {yughmoH} “include (that is, cause to be included).”  So {X neH yughmoH} “filter for X only, include X only.”

Neither {Hal} nor {mung} would be “source” in the literary sense (which I take to mean where a particular entry in boQwI’ comes from). This would be {nompuq} “authority, evidence, attestation, reference, citation.” 

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