If you don’t know if your AdvancedContentManager version support the search feature, please check the release notes.
In AdvancedContentManager, you can enable the search option by ContentType. However, only the Content can be searchable. It is planned to add the ContentLists to the indexers too.
Firstly, you need to enable the search option in your ContentType, in the tabs “Search”. Now, some new fields are available in your CustomFields, “Is Searchable” and “Search Attribute Weight”.
The first field allows you to set this attribute searchable or not. The second allows you to define the weight of the attribute in the search algorithm.
Save your ContentType. If the Content Manager Search index is configured to “update on save”, your Contents are available in the search form. Else, wait for the cron to reindex the Content Manager Search index. You can also reindex the Content Manager Search index manually. If so, please run the following command in the root of your Magento 2 project:
php bin/magento indexer:reindex blackbird_contenttype_fulltext