Y axis Constant Line

Hi,Jihwan_Kim 

thanks for your concern about this issue. 

Your answer is excellent! 

Hi,Anonymous 

I am glad to help you. 

According to your description, you want to know why you are trying to add a constant line you are getting the option of X-axis constant line only? 

If I understand you correctly, then you can refer to my solution. 

I'm sorry to tell you that after my repeated tests, I can't get the results you want in Power BI, because the values of your two line charts are not standardized metrics: one takes the value of the bar chart and the other takes the value of the percentage. 

So I assumed a Measure when testing, which is what I got from the test: 

I hope my suggestions give you good ideas, if you have any more questions, please clarify in a follow-up reply.

Best Regards,
Fen Ling,

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.