Intuitionistic　fuzzy　sets　(IFSs)　are　key　concepts　in　ambiguity　and　uncertainty.　However,　IFSs　deal　only　with　anticipation,　not　periodicity.　To　do　so,　complex　intuitionistic　fuzzy　sets　(CIFS)　can　handle　uncertainties　and　periodicity　simultaneously.　Also,　the　Maclaurin　symmetric　mean　(MSM)　operator　is　a　better　tool　for　dealing　with　the　criteria＇s　interrelationships.　As　a　result,　this　article　presents　a　multi-criteria　decision-making　(MCDM)　approach　in　the　CIFS　setting,　which　draws　inspiration　from　the　CIFS　and　MSM　operators.　We　develop　complex　intuitionistic　fuzzy　partitioned　dual　Maclaurin　symmetric　mean　(CIFPDMSM)　operators　and　their　weighted　form　by　considering　that　all　the　criteria　can　be　arranged　into　some　groups.　The　proposed　operators　deal　not　only　with　interrelationships　between　criteria　but　also　with　partitioned　relationships　among　criteria.　Some　properties　of　the　proposed　operators　are　discussed　in　detail.　Further,　an　MCDM　approach　is　developed　based　on　the　proposed　operators　in　the　CIFS　environment.　To　show　the　effectiveness　and　application　of　the　developed　method,　we　also　present　a　numerical　example　for　selecting　computer　network　security　systems.　Finally,　the　method　is　compared　with　the　existing　technique　to　demonstrate　the　proposed　method＇s　applicability　and　feasibility.