There are two timescales to finance building a multiplex. There is development, a short period that has no income, and operating, a long period with income.
The development period will be financed with short term community bonds. Community bonds are sold to people with money who support the aims of the project. They pay interest, typically below market rate.
The operating period will be financed through member loans (5% of capital costs) and mortgages provided by a finance co-op that will sell variable rate bonds to raise the funds for the mortgages.