meaning - What is the correct way to use "neither" and "nor" in a sentence together?

You need to either use a negative verb ("cannot"), or use neither/nor. Using the two together, like what that editor did to your post in TeX, is incorrect.

I can find the tool neither in the kitchen nor the bathroom.

I can't find the tool either in the kitchen or the bathroom.

I can't find the tool neither in the kitchen nor the bathroom.

I do want to note that, unless the context leads the reader to expect a negative, the "can find ... neither" version can be confusing. Thus, "can't find ... either" is in most cases the better choice.