trigger relatedrecord on channel__c (before insert, before update) {
Set<Id> caNotetoTLX = new Set<Id>();
Set<Id> newCreatedCAIds = new Set<Id>();
Set<Id> allCustomerIds = new Set<Id>();
Id caseID ;
ID CustId;
    if (trigger.isBefore ){
    List<channel__c> insertCA = new List<channel__c> ();

    for(channel__c ca : Trigger.New) {
     caseID = ca.case;
     newCreatedCAIds.add(caseID);
 }
        List<case> colletionIds = [SELECT id,AccountId FROM case WHERE Id= :newCreatedCAIds];
    List<case> relatedcase= new List<case>();

    for(case cases: colletionIds){
    CustId = cases.AccountId;
    allCustomerIds.add(CustId);
    }
    relatedcase = [Select id, AccountId from case where AccountId= :allCustomerIds AND id <> :caseID ];
    List<channel__c> insertNewchannel = new List<channel__c>();

    for(case ca :relatedcase){
     channel__c  channel = new channel__c();
     channel.Action__c = 'Reviewed Account';
     channel.case =ca.id;
     insertNewchannel.add(channel);
    }
    }
    }