You can take many approaches to how you filter your search by industry, but this decision should be influenced by what you believe your personal value add will be.

Somebody with a long career in a certain industry may have a very specific thesis they want to pursue with their search, so naturally they will seek targets with a narrow set of characteristics related to that thesis. If you have good industry experience but don't yet have a defined investment thesis, a natural approach could be to start with your familiar industry, tap into its various subsectors, then expand up/down/across that industry's value stream as needed to keep the pipeline healthy and as you get more knowledgeable about other areas of the sector.

On the other hand, some searchers are successful with broader/more opportunistic approaches or by filtering on criteria other than industry (e.g. looking for certain business models while only considering end-market as a secondary factor). If, for example, you think your main value add will be bringing leadership and professional management to an undermanaged business, perhaps you can look at deals across a much broader set of end markets.

How big is the TAM of potential sellers in your industry? If it is big enough it would be definitely better to search in an industry you already know. If the number of potential companies to buy is small and none wants to sell, the search would be over pretty soon. Best of luck.