Gitlab-CI: variable in variable in downstream trigger job - gitlab-ci

Question

(How) Can I use variable value as a name for another variable?
I have a job with matrix and dotenv artifacts as follows:
build-names:
stage: build
...
script:
...
<lines omitted>
...
- echo "${NAME}_DEB_PACKAGE_VERSION=${DEB_PACKAGE_VERSION}" >> build.env
artifacts:
reports:
dotenv: build.env
parallel:
matrix:
- NAME:
- name1
- name2
type:
- 0
- 1
environment: $NAME/$TYPE
Then I have a downstream trigger job again using matrix and I want to pass the appropriate package version based on the ${NAME}
build-images:
stage: .post
needs:
- job: build-names
artifacts: true
variables:
PACKAGE_VERSION_VARIABLE_NAME: ${NAME}_DEB_PACKAGE_VERSION
PACKAGE_VERSION: ${${BACKEND_VERSION_VARIABLE_NAME}}
// OR
PACKAGE_VERSION_VARIABLE_NAME: ${NAME}_DEB_PACKAGE_VERSION
PACKAGE_VERSION: ${!BACKEND_VERSION_VARIABLE_NAME}
trigger:
project: group/project-${NAME}
parallel:
matrix:
- NAME:
- name1
- name2
Neither of the two approaches above (double ${${}} or !) works in the variables section.
I could 'generate' the variable within script section, but AFAIK you cannot have both trigger and script within the same job.
Is there a workaround for similar use cases?
(Using self-hosted gitlab 15.4)