Mixed ballot transferable vote

Other members are elected on a compensatory national (upper) tier from a list and voters cast a single ballot where they may indicate their preferences separately.

How proportional the outcome is depends on among other factors, the rules (what counts as "wasted" vote) and parameters (e.g. the number of compensatory seats) used in the system.

The simplest type of MBTV system allows two single choices on the ballot: one for a local candidate, one for a party list.

The rest of those ballots are considered to have been cast for the party of those candidates who got elected, which avoids split ticket voters double voting power.

[6] This mechanism makes it similar to the preferential interpretation of the mixed ballot when it would be used in a purely vote linkage based system.

MBTV uses a mixed ballot, on which candidate and list votes can be indicated separately, but are jointly treated as mixed single vote in the vote linkage compensation.
A mixed ballot used in the 2005 elections to the German Bundestag