SubsetMap

SubsetMap[f,{e1,e2,…},{i,j,…}] yields an expression in which the elements ei, ej, … in the list {e1,e2,…} are replaced with the corresponding elements of the list obtained by evaluating f[{ei,ej,…}].

SubsetMap[f,expr,{pos1,pos2,…}] replaces elements of expr at positions pos1, pos2, ….

SubsetMap[f,{pos1,pos2,…}] represents an operator form of SubsetMap that can be applied to an expression.

Please visit the official Wolfram Language Reference for more details and examples on core symbols.