What the command was...:
/tp @a[x=~5,y=~0,z=~5] ~10 ~ ~
What I expected to happen was...:
If I was standing x=~5, y=~0, z=~5 from the command block when it is activated, I would be teleported x=~10, y=~0, z=~0 from where I was standing.
What actually happened was...:
I was not teleported.
Steps to Reproduce:
1. Enter "/tp @a[x=~5,y=~0,z=~5] ~10 ~ ~" in a command block.
2. Activate the command block when you are standing x=~5,y=~0,z=~5 in relation to the command block. (I used a /fill clock.)
3. Hope to be teleported.
When working with target selectors, you must use absolute coordinates rather then relative. Try this for example:
/tp @a[x=10,y=64,z=10] ~10 ~ ~
This will teleport all players on that coordinate.