Hi Viktor,

I've just come across your question, and for this specific requirement, you have to build custom filters. You can try an example like this:

// Build the first level filter
var level1Filter = _searchClient.BuildFilter<T>();

// Build the second level filter
var level2FilterA = _searchClient.BuildFilter<T>();
level2FilterA = level2FilterA.And(x => <<your filter expression>>);
level2FilterA = level2FilterA.Or(x => <<your filter expression>>);

var level2FilterB = _searchClient.BuildFilter<T>();
level2FilterB = level2FilterB.And(x => <<your filter expression>>);
level2FilterB = level2FilterB.Or(x => <<your filter expression>>);

// Combine the two second level filters A & B to the first level filter
level1Filter = level1Filter.And(t => level2FilterA);
level1Filter = level1Filter.And(t => level2FilterB);

// Apply the first level filter to your query
query = query.Filter(level1Filter );

If you use Typed Search, then the generic T here is your strong typed model, and if you use Unified Search, then T should be of type ISearchContent.

Basically it is to build nested filters, so you will have the effect just like the parentheses :)

Cheer!