By analyzing an electron-positron collision data sample corresponding to an integrated luminosity of 2.93 fb-1 taken at the center-of-mass energy of 3.773 GeV with the BESIII detector, we obtain for the first time the absolute branching fractions for seven D0 and D+ hadronic decay modes and search for the hadronic decay D0→KS0KS0π0 with much improved sensitivity. The results are B(D0→KS0π0π0π0)=(7.64±0.30±0.29)×10-3, B(D0→K-π+π0π0π0)=(9.54±0.30±0.31)×10-3, B(D0→KS0π+π-π0π0)=(12.66±0.45±0.43)×10-3, B(D+→KS0π+π0π0)=(29.04±0.62±0.87)×10-3, B(D+→KS0π+π+π-π0)=(15.28±0.57±0.60)×10-3, B(D+→KS0π+π0π0π0)=(5.54±0.44±0.32)×10-3, B(D+→K-π+π+π0π0)=(4.95±0.26±0.19)×10-3, and B(D0→KS0KS0π0)<1.45×10-4 at the 90% confidence level. Here, the first uncertainties are statistical, and the second ones are systematic. The newly studied decays greatly enrich the knowledge of the D→K̄πππ and D→K̄ππππ hadronic decays and open a bridge to access more two-body hadronic D decays containing scalar, vector, axial, and tensor mesons in the charm sector. © 2022 authors. Published by the American Physical Society.