Import can build a hierarchy (a tree) of items from the import data. This hierarchy is built from a column which contains indented data. The indentation levels will be used to determine the parent-child relationship of the items. Use Excel's indent button to add indentation in a cell or use tabs in CSV files for building hierarchies.

Use the "indent" button of Excel located in the Excel toolbar:

For example if the "name" column contains this data in this indentation:

Then the 4 created issue will be in the same parent-child hierarchy, i.e. the BANANA will be child of APPLE and PLUM will be child of PEACH Like this:

See also: Excel Round-trip and Excel import and Exporting hierarchy of Work items to Excel using custom templates