Hi Simon,

I've not worked with the blocklist myself, but i think you can add a custom field to the external index of umbraco with the values you need from your blocklist. For example you could create a custom index field with the value of all the blocklist items combined to search on.

    public class IndexComposer : ComponentComposer<IndexComponent>
    { }

    public class IndexComponent : IComponent
    {
        private readonly IExamineManager _examineManager;
        private readonly IUmbracoContextFactory _umbracoContextFactory;

        public IndexComponent(IExamineManager examineManager, IUmbracoContextFactory umbracoContextFactory)
        {
            _examineManager = examineManager;
            _umbracoContextFactory = umbracoContextFactory;
        }

        public void Initialize()
        {
            if (_examineManager.TryGetIndex(Constants.UmbracoIndexes.ExternalIndexName, out IIndex index))
            { 
                index.FieldDefinitionCollection.AddOrUpdate(new FieldDefinition("blockListTitles", FieldDefinitionTypes.FullText));

                if (index is BaseIndexProvider baseIndex)
                {
                    baseIndex.TransformingIndexValues += OnTransformingIndexValues;
                }
            }
        }

        private void OnTransformingIndexValues(object sender, IndexingItemEventArgs e)
        {
            if (e.ValueSet.Category != IndexTypes.Content) return;

            using (var context = _umbracoContextFactory.EnsureUmbracoContext())
            {
                var contentId = int.Parse(e.ValueSet.Id);
                var content = context.UmbracoContext.Content.GetById(contentId);

                if (content is BlocklistPage contentPage) // Your page type
                {
// Add some checks if the page has any blocklist items
                    var blocks = contentPage.Value<IEnumerable<BlockListItem>>("myBlocksProperty");
                    e.ValueSet.Add("blockListTitles", string.Join(",", blocks.Select(x => x.Content.Value("contentTitle"))));
                }
            }
        }

        /// <summary>
        /// There is no termination logic for this component
        /// </summary>
        public void Terminate()
        { }
    }

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