I suspect your question is related to your other question at Canvas : Need to parse the values of 2 filters to the essql.
In short, there's not currently a way to apply filters as an OR argument in a query. What this means is that if you create two different filters and use them in the expression, they will be used as an AND condition. So this means something like filters | essql ...isn't an option currently.
The alternative method would be to somehow use the filter values in the sql query itself, something like essql {string "SELECT ... WHERE " {filters | to string}} .... The idea is that you could capture the filter values and just use them in the query string. This is also a non-option as there's no way to map a filter's value into a string value, so it can't be substituted into the query string.
This is all a pretty round-about way to tell you you can't do what you're trying to do in Canvas, at least not today. I'll admit that this does seem like a perfectly natural request though, and I'd recommend opening an issue about it on Kibana's issue tracker. Supporting OR in filters would enabled what you want, without having to modify the query directly, and that seems like a feature we should add, and soon.