Step 1: Search for examples of what is called a Master Calendar in Qlik. Essentially it is something you do in your load script so that each row would say "I'm in week 14. I'm in Quarter 3. I'm in Month 7 .... etc." That way you don't have to do a lot of complex coding in your charts as most of the CPU work would already be done.
Step 2: Within Qlik you can combine Aggregation operations like Sum with IF expressions. So for example a KPI could do SUM(MyFieldValue) to get the overall total for every row. But if you just wanted the SUM of the values for Quarter 4 you could say SUM(IF(QuarterNumber = 4, MyFieldValue, 0) )
Step 3: If you really want to get fancy in your load script you would build FLAGs. Binary 0 or 1 values. For example you would build a Q4 flag and only the rows of data that are in Q4 would be set to 1. Then you can do simple match in your expression SUM(Q4Flag * MyFieldValue)
Step 4: A more advanced way to that type of thing as you grow in Qlik Sense is called Set Analysis. It would allow you to do the same thing as step 2 but handle cases where your end user filters to a Date value that is in Quarter 1 and your end users say "I need to see all of the high level SUM's no mater what date I select". I don't recommend you do it now, but be sure to bookmark this post I created which includes an entire hands on workshop when you become more familiar with Qlik Sense. https://community.qlik.com/t5/Documents/Hands-on-Set-Analysis-from-the-ground-up/ta-p/1799118
