Subtask support depends on the tool you are using, while some tools support infinite levels of subtasks (e.g. Wrike) other doesn't support subtasks at all (e.g. Github).

Sub-sub-sub-and-more-subtasks

Unito syncs only one level of substaks.

Sub-subtasks (level ≥ 2), when replicated into a one-level-only tool, will be ignored. Rest assured though, the full subtask hierarchy inside the original tool will remain unaffected.

Trello

While Trello does not have subtasks, they do have checklists, which Unito will fully sync to other checklists or subtasks.

Asana

Unito sync Asana subtasks, one level deep.

Github

Github does not support subtasks. Subtasks will therefore not be synced into Github, but will not be deleted in the origin tool.

JIRA

JIRA supports only one-level deep subtasks. They are synced with other tools supporting one-level deep subtasks (e.g. Asana) and tools that support infinite-level deep subtasks (e.g. Wrike).

Wrike

Unito sync Asana subtasks, one level deep.

Here is an example of subtask hierarchy in Wrike:

Once synced, this is how it will appear in JIRA, that doesn't support sub-subtasks:

Multiple Parents

Wrike supports putting a subtask under multiple parent tasks. When replicated onto another tool supporting one-level deep subtasks, the subtask will be put under the highest ancestor task that is also part of the folder being synced.  If the Wrike subtask doesn't have any parent/ancestor in the current project, the subtask will be replicated as a regular issue on the other tool.

Advanced Operations: Changing the Subtask's Parent,
Converting a Subtask to a Task & Vice Versa

Sometimes you need to move a subtask to another parent, demote a task to subtask level, or promote a subtask to a full-blown task. These advanced operations are possible in both Wrike and JIRA.

Any such change on the JIRA side will be carried over to the Wrike side. However, due to limitations of the JIRA API, if these operations are applied from Wrike, the synchronization process will not apply the change automatically on JIRA.