Question: For some reason I feel its overkilling on the use of article(the) here, 

> 
> To refine the results, please use the categories on the left
> 
> 
> 

Can someone help?

Answer: 
As others have said, your sentence is fine, as-is.

However, you might change it to "To refine *your* results, please use the categories on the left."

This would mitigate your concerns with the repeated "the".
@shin is correct. "The" is used three times in the sentence. Each time "the" is used, the word that follows "the" gets qualified, becomes specific. The sentence is ok. There is no overuse of "the".