Hi Jonas,
If I understand correctly, your period represents a week of the year but you appear to be using an x-axis dimension that has Period/Fiscal Year compounded. Do you have a Period dimension that is based only on the week number (1-52)? This is the only way you will be able to superimpose the three KPI measures on the same chart.
It looks like your data source is BEx, so in that case, I would suggest a query structure as follows:
1) KPY Y Key Figure restricted to Current Fiscal Year (YYYY) Variable
2) KPY Y-1 Key Figure restricted to Current Fiscal Year (YYYY) Variable - 1
3) KPY Y-2Key Figure restricted to Current Fiscal Year (YYYY) Variable - 2
4) Chart X dimension specified as Period representing week only (1 -52) without Fiscal Year compounded
Regards,
Mustafa.