RTL

You can make the tree right to left easily by using custom CSS.
Example:

sample.component.html

<tree-root class="rtl" [focused]="true" [nodes]="nodes"></tree-root>

styles.scss

.rtl {
    direction: rtl;
    .toggle-children-wrapper-collapsed .toggle-children {
        transform: rotate(180deg) !important;
    }
    .tree-children {
        padding-right: 20px;
        padding-left: 0;
    }
}