The metadata search filter on documents. Returns chunks only from documents which match the filter. The following filter operators are supported: $eq - Equal to (number, string, boolean), $ne - Not equal to (number, string, boolean), $gt - Greater than (number), $gte - Greater than or equal to (number), $lt - Less than (number), $lte - Less than or equal to (number), $in - In array (string or number), $nin - Not in array (string or number). The operators can be combined with AND and OR. Read Metadata & Filters guide for more details and examples.