Issues of sub-national referendums regulated at the national level

Paraguay
Answer
None
Source
Paraguay's Constitution of 1992 with Amendments through 2011
https://www.constituteproject.org/constitution/Paraguay_2011
ElectoralCode (Código Electoral Paraguayo – Ley No 834-96)
http://www.oas.org/es/sap/deco/moe/Paraguay2013/docs/CODIGO_ELECTORAL.pdf
Comment
No provision was found in this regard