Looks like you're in need of concatenation.
Concatenation is possible in two ways accounting for whether both of your Clients tables have exactly the same fields.
Here is a resource with some examples: Concatenate Tables Qlik Sense 3.1
ClientID as CommonClientID,
ClientID &'_'&ClientOfficeID as CommonClientID,
ClientID &if(ClientOfficeID = 0 or isnull(ClientOfficeID ) ,'','_'&ClientOfficeID ) as CommonClientID
LOAD * RESIDENT ClientS;
Drop table ClientS;
this solution won't work!
while using the second join Statement there are two fields that are existing in Sales tab:
TotvsID AND Client Name (resulting from the first join).
So no dataset will be joined!
Be careful with joining, often it isn't neccessary. Think in tables and linked fields.