# tmux_select:filter/2

- **Package:** libtmux_erlang
- **Language:** Erlang
- **Kind:** function
- **Source:** https://github.com/libtmux/libtmux-erlang/blob/d1b6308440cf9eb8f6647e7ae434bce60e849368/apps/libtmux_erlang/src/tmux_select.erl#L142
- **Page:** https://libtmux.org/en/erlang/latest/reference/tmux_select-filter-2/

```
filter/2
-spec filter(fun((Row) -> boolean()), t(Row)) -> t(Row)
                when Row :: tmux_model:row().
```

Apply an ordinary unary Boolean function locally, preserving row order and context. Non-Booleans and callback failures propagate; they are not false matches. This is executable application code, not portable filter data.

## Parameters

- `Predicate` (`fun((Row) -> boolean())`)
- `Selection` (`t(Row)`)

## Guides

Pages that discuss `filter/2`.

- [Selections and queries](/en/erlang/latest/concepts/queries/)