SelectionButton.kt

Box(modifier = modifier.width(boxWidth)) {
    // this is the background that moves to hightlight what's currently selected
    Box( 
        modifier = Modifier
            .offset(x = selectionOffsetX)
            .width(selectionWidth)
            .height(buttonHeight)
            .background(Purple20, selectionShape)
    )

    Row {
        Button(
            modifier = Modifier
                ...
                .clickable(
                    // remove ripple from button
                    interactionSource = remember { MutableInteractionSource() },
                    indication = null,
                    onClick = { onSelected(...) }
                )
        )
        Button(
            modifier = Modifier
                ...
                .clickable(
                    interactionSource = remember { MutableInteractionSource() },
                    indication = null,
                    onClick = { onSelected(...) }
                )
        )
    }
}