The field setting "Boost" will boost the values in the search and helps you define the relevance of the content for your users. The boost parameter increases the relative weight of a term (with higher boost values) or decreases the relative weight (with lower boost values), but the increase or decrease is not linear. In other words, a boost of 2 does not result in double the score. You can select between 1, 10, 25, 50, 100, or 500.
Boosting in a list is for the search in fields while tagging.
Boosting in layers is for the content browser search.
Picturepark checks this setting against the allowed number of Search-indexed fields in your subscription plan. While it may be tempting to include all fields in filters and simple search also boosting them, you may revisit this idea based on your subscription plan limit.