HELP! IPointerClickHandler event；How to set the hierarchy？

I created two tilemap and one sprite，all implement IPointerClickHandler，
1. tilemap: poistion.z=4,order in layer = 5
2. sprite: poistion.z=0,order in layer = 8
3. tilemap: poistion.z=-1,order in layer = 11

Now，I click on the overlap of sprite and tilemap，Each time the event of the sprite；
If you click the non sprite position，It's based on poistion.z trigger event;
What should I do？

 

In addition, unity version is 2019.4.2f1

 

To sum up, I have a tilemap above the sprite, and I can't click the tilemap in the overlapping area;