Hi Stanislaw,

Actually, there are a lot of ways to build where condition such as using builtin filter expression, delegate filter builder with Optimizely Graph Client package. We can use AndFilter, OrFilter or use Bit operator such as &, | to make condition as group. Sometimes, we also need to combine some different ways, create new delegate filter builder to build our complicated condition.

With your requirement, you can do it by this following way:

var orFilter = BooleanFilter.OrFilter<GraphModels.Content>().Or("_fulltext", new StringFilterOperators().Match(q))
    .Or("Name", new StringFilterOperators().Match(q).Fuzzy(false).Boost(10));

var result = _contentGraphClient
.OperationName("Alloy_Sample_Query").ForType<GraphModels.Content>()

.Where(x => orFilter & x.ContentType.In(new [] { "NewsPage", "ArticlePage" }))

.Fields(_ => _.Name, _ => _.Url)
.Facet(_ => _.ContentType)
.Total()            
.GetResultAsync<GraphModels.Content>().Result;

You can check other information about "where" filter here https://docs.developers.optimizely.com/platform-optimizely/v1.4.0-optimizely-graph/docs/where-filter

I did it with a few custom filters classes.

Here's an example:

public class GroupedOrFilter : Filter
{
    private readonly List<string> _orFilters = [];

    public override string FilterClause
    {
        get
        {
            string combinedFilters = string.Join("}{", _orFilters);

            return $"_and:[{{{combinedFilters}}}]";
        }
    }

    // Method to add an OR filter block inside an AND block
    public GroupedOrFilter And(OrFilter orFilter)
    {
        _orFilters.Add(orFilter.FilterClause);
       
        return this;
    }
}