Help-Need to create a custom split on date

Hi Tableau friends!

Need some help.

I have a date dimension that is a string called CAL_QUARTER_DESCR. It shows a year and quarter combination like this:

2017 Qtr 1

2017 Qtr 2

2017 Qtr 3

2017 Qtr 4

I want to split off the year by itself as a whole number dimension so that dimension renders this:

2017

2018

Next I want to split off the quarter as a string dimension....but here's the tricky part....I want it to look like this:

Q1

Q2

Q3

Q4

I don't want Qtr 1......I want Q2 on that dimension split

So how can I convert the quarter from the way it's given to me as Qtr 1 and make it Q1 when doing a custom split

My data is highly protected info so I can't share a workbook. So I'm hoping someone can help me do this by the description I just listed.