pane.Pane.split

const created = await pane.split({ vertical: true });
created.id;

>>> (pane.at_left, pane.at_right,
...  pane.at_top, pane.at_bottom)
(True, True,
True, True)

>>> new_pane = pane.split()

>>> (new_pane.at_left, new_pane.at_right,
...  new_pane.at_top, new_pane.at_bottom)
(True, True,
False, True)

>>> right_pane = pane.split(direction=PaneDirection.Right)

>>> (right_pane.at_left, right_pane.at_right,
...  right_pane.at_top, right_pane.at_bottom)
(False, True,
True, False)

>>> left_pane = pane.split(direction=PaneDirection.Left)

>>> (left_pane.at_left, left_pane.at_right,
...  left_pane.at_top, left_pane.at_bottom)
(True, False,
True, False)

>>> top_pane = pane.split(direction=PaneDirection.Above)

>>> (top_pane.at_left, top_pane.at_right,
...  top_pane.at_top, top_pane.at_bottom)
(False, False,
True, False)

>>> pane = session.new_window().active_pane

>>> top_pane = pane.split(direction=PaneDirection.Above, full_window_split=True)

>>> (top_pane.at_left, top_pane.at_right,
...  top_pane.at_top, top_pane.at_bottom)
(True, True,
True, False)

>>> bottom_pane = pane.split(
... direction=PaneDirection.Below,
... full_window_split=True)

>>> (bottom_pane.at_left, bottom_pane.at_right,
...  bottom_pane.at_top, bottom_pane.at_bottom)
(True, True,
False, True)

use libtmux::{PaneSize, SplitDirection, SplitOptions};

let session = server.new_session("split-from-pane").await?;
let pane = session.panes().await?.remove(0);

let above = pane
    .split(
        SplitOptions::new(SplitDirection::Above)
            .size(PaneSize::Percent(30))
            .command("sleep 300"),
    )
    .await?;

assert_ne!(above.id(), pane.id());
assert_eq!(above.window_id(), pane.window_id());