## parseFilterParameter() function

Parses a FHIR _filter parameter expression into an AST.

**Signature:**

```typescript
export declare function parseFilterParameter(input: string): FhirFilterExpression;
```

## Parameters

| Parameter | Type   | Description                                        |
|-----------|--------|----------------------------------------------------|
| input     | string | The FHIR _filter parameter expression.             |

**Returns:**

[FhirFilterExpression](/content/docs/sdk/core.fhirfilterexpression)

The AST representing the filters.