# Restricting to a lower navigation level

Deeper navigation – or navigation at a lower level – requires a combination of filters to be passed when first calling the FactFinder Navigation module.

Filtering for a simple data field

When submitting a deeper navigation call, you must ensure that the entire filter combination is passed in the correct sequence. When filtering using data fields, it is important that you know which FactFinder field contains the corresponding levels, and which field name refers to the corresponding field. Let us assume that the categories are distributed in the fields `category0, category1` and `category2`, where `category0` is the top level of navigation.

So, for example, if the navigation is to go from the top-level category Clothing to the subcategory Trousers and then to a further sub-category `Jeans`, the call to the REST interface should be as follows:

```language-plaintext
$stringEscapeUtils.escapeHtml($body)
```

```language-plaintext
$stringEscapeUtils.escapeHtml($body)
```

```language-plaintext
$stringEscapeUtils.escapeHtml($body)
```

### Filtering for a category path field

By complying with the schema below it is possible to generate all filters required for deeper navigation from the field names and selected navigation path..

**Schema:** FILTER\_NAME:VALUE1/VALUE2/.../VALUEX.

Please note the suffix `ROOT` after the filter parameter.

In our example, the resulting filter has the name `categoryROOT/Clothing` and the value `Trousers`, which must be passed in addition to the main category filter. (To improve the readability of these examples, the slashes in the example URLS have not been encoded.)

```language-plaintext
$stringEscapeUtils.escapeHtml($body)
```

```language-plaintext
$stringEscapeUtils.escapeHtml($body)
```

```language-plaintext
$stringEscapeUtils.escapeHtml($body)
```