It's possible to create a multi select formula field to show the unique entries. There would be a multi select field look up from the parent, a multi select field on the child which is a data entry field and then a final formula multi select field which would have the unique entries.
I have this formula wich might work
var text RawList = List(" ; ",
ToText([Parent multi select lookup]),
ToText([Child Multi select]));
var text A = Trim(Part($RawList,1,";"));
var text B = If(not Contains($A,Trim(Part($RawList,2,";"))), List("\n", $A, Trim(Part($RawList,2,";"))), $A);
var text C = If(not Contains($B,Trim(Part($RawList,3,";"))), List("\n", $B, Trim(Part($RawList,3,";"))), $B);
var text D = If(not Contains($C,Trim(Part($RawList,4,";"))), List("\n", $C, Trim(Part($RawList,4,";"))), $C);
var text E = If(not Contains($D,Trim(Part($RawList,5,";"))), List("\n", $D, Trim(Part($RawList,5,";"))), $D);
var text F = If(not Contains($E,Trim(Part($RawList,6,";"))), List("\n", $E, Trim(Part($RawList,6,";"))), $E);
var text G = If(not Contains($F,Trim(Part($RawList,7,";"))), List("\n", $F, Trim(Part($RawList,7,";"))), $F);
var text H = If(not Contains($G,Trim(Part($RawList,8,";"))), List("\n", $G, Trim(Part($RawList,8,";"))), $G);
var text I = If(not Contains($H,Trim(Part($RawList,9,";"))), List("\n", $H, Trim(Part($RawList,9,";"))), $H);
var text J = If(not Contains($I,Trim(Part($RawList,10,";"))), List("\n", $I, Trim(Part($RawList,10,";"))), $I);
var text K = If(not Contains($J,Trim(Part($RawList,11,";"))), List("\n", $J, Trim(Part($RawList,11,";"))), $J);
var text L = If(not Contains($K,Trim(Part($RawList,12,";"))), List("\n", $K, Trim(Part($RawList,12,";"))), $K);
var text M = If(not Contains($L,Trim(Part($RawList,13,";"))), List("\n", $L, Trim(Part($RawList,13,";"))), $L);
var text N = If(not Contains($M,Trim(Part($RawList,14,";"))), List("\n", $M, Trim(Part($RawList,14,";"))), $M);
var text O = If(not Contains($N,Trim(Part($RawList,15,";"))), List("\n", $N, Trim(Part($RawList,15,";"))), $N);
var text P = If(not Contains($O,Trim(Part($RawList,16,";"))), List("\n", $O, Trim(Part($RawList,16,";"))), $O);
var text Q = If(not Contains($P,Trim(Part($RawList,17,";"))), List("\n", $P, Trim(Part($RawList,17,";"))), $P);
var text R = If(not Contains($Q,Trim(Part($RawList,18,";"))), List("\n", $Q, Trim(Part($RawList,18, ";"))), $Q);
var text S = If(not Contains($R,Trim(Part($RawList,19,";"))), List("\n", $R, Trim(Part($RawList,19,";"))), $R);
var text T = If(not Contains($S,Trim(Part($RawList,20,";"))), List("\n", $S, Trim(Part($RawList,20,";"))), $S);
var text U = If(not Contains($T,Trim(Part($RawList,21,";"))), List("\n", $T, Trim(Part($RawList,21,";"))), $T);
var text V = If(not Contains($U,Trim(Part($RawList,22,";"))), List("\n", $U, Trim(Part($RawList,22,";"))), $U);
var text W = If(not Contains($V,Trim(Part($RawList,23,";"))), List("\n", $V, Trim(Part($RawList,23,";"))), $V);
var text X = If(not Contains($W,Trim(Part($RawList,24,";"))), List("\n", $W, Trim(Part($RawList,24,";"))), $W);
var text Y = If(not Contains($X,Trim(Part($RawList,25,";"))), List("\n", $X, Trim(Part($RawList,25,";"))), $X);
var text Z = If(not Contains($Y,Trim(Part($RawList,26,";"))), List("\n", $Y, Trim(Part($RawList,26,";"))), $Y);
$Z
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Mark Shnier (YQC)
Quick Base Solution Provider
Your Quick Base Coach
http://QuickBaseCoach.commark.shnier@gmail.com
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